those yellow stripe wires were not "commin" in the 50's, the 57 would have had black plug wires with the straight plug boots [look for pics in your manuals], you should be able to find a set at a FLAPS like this

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature we find it attached to the rest of the world" John Muir
"When we tug a single thing on an old truck, we find it falls off" me
Some TF series details & TF heater pics & Rust-a-holics Unanimous parking lot